API Line input question

[Studio Mollan]

Hi,
I have a question about a few diodes on the line input in the vintage API desks.
I took a screen grab from another thread here with a clear schematic. D1-4.
My question is: Why are they there at all?

 

[ruffrecords]

The intention is to prevent the input signal exceeding the power supply rails.

Cheers

Ian

 

[Studio Mollan]

Thanks Ian.
What would be the practical purpose of this?

The intention is to prevent the input signal exceeding the power supply rails.

Cheers

Ian

 

[john12ax7]

The purpose is to protect the circuit that follows,  perhaps an opamp in this case. Transistors have max ratings,  for example Vcb., which you don't want to exceed.

 

[Studio Mollan]

Alright thanks!

The purpose is to protect the circuit that follows,  perhaps an opamp in this case. Transistors have max ratings,  for example Vcb., which you don't want to exceed.

 

[buildafriend]

This is called diode clamping